This invention comes within the field of crankshaft machining and concerns, in particular, a machine tool for turning and shaving crankshafts for engines.
The present machine tools for turning and shaving crankshafts designed for engines are of the type comprising a frame that contains a work station ensuring the rotation of a crankshaft and a machining station equipped with at least one tool holder for turning and shaving the crankshaft driven in rotation on the work station. The machining station and the drive station are generally arranged on an inclined plane in order to facilitate the extraction of shavings resulting from the machining operation.
Such a machine tool has a disadvantage as to its profitability, for a time delay is necessary between two machining operations on the same machine, in order to assume all of the operations of disengagement, unloading, loading, engagement and indexing of a crankshaft, called "auxiliary operations" within the context of this invention. For the turning and shaving of crankshafts designed for engines with four in-line cylinders, the applicant found that the times of the auxiliary operations were as long as the machining times, so that the effective machining times are cut in half, which is very detrimental to the efficiency of such machine tools.
On the basis of these findings, the applicant then conducted research which led to the study of a new machine tool design making it possible to overcome this type of problem, while offering numerous other advantages intended to improve the machining of crankshafts both quantitatively and qualitatively.
Although such a machine tool was conceived in the minds of the innovators to perform the operations of turning and shaving of crankshafts for engines with four in-line cylinders, it goes without saying that its basic concepts, which are going to be described and represented below for this specific type of application, may be easily adopted by the expert for other types of machining (grinding, simple turning, etc.) and other types of crankshafts.